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| Begonia tui T.N.Bon & C.W.Lin, in Bon, Gratzfeld, Tuyet et Lin, 2023. |
Abstract
Begonia tui, a new species of sect. Coelocentrum, is described and illustrated here. It was collected during expeditions carried out on a limestone hill in Quang Binh Province, Central Vietnam. The new species is morphologically similar to B. mollissima in its rugose, widely ovate lamina. However, the new species can be distinguished by the margin of the stipule which is entire (vs. ciliate), androecium is zygomorphic (vs. actinomorphic), the pistillate flowers with 3 tepals (vs. 2), and the ovary's abaxial wing is triangular (vs. lunate). The conservation status of B. tui is assessed as Endangered, according to the IUCN Red List Categories and Criteria.
Keyword: Begonia mollissima, Begonia datii, biodiversity, endemism, Indochina, limestone, taxonomy, plant conservation
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| Begonia tui T.N.Bon & C.W.Lin. A. Habit; B, B'. Portion of leaf adaxial and abaxial surfaces; C. Stipule; D-D'''. Bracts; E, E'. Staminate flower, face and side views; F, F'. Stamens, ventral and dorsal views; G, G'. Pistillate flower, face and side views; H, H'. Style and stigmatic band, dorsal and ventral views; I. Capsule; J. Cross section of ovary. |
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| Begonia tui T.N.Bon & C.W.Lin. A. Habit and habitat; B. Habit; C. Rhizome; D. Stipule, also showing petioles and juvenile leaf; E. Immature inflorescence, also showing bract; F. Portion of leaf adaxial surface, G. same, abaxial surfaces; H. Staminate flowers, face, back and side views; I. Pistillate flowers, face and side views; J. Inflorescence and infructescence; K. Capsule; L. Cross section of ovary. |
Begonia tui T.N.Bon & C.W.Lin, sp. nov.
§ Coelocentrum
Diagnosis: Begonia tui resembles B. datii T.S.Hoang & C.W.Lin in the rhizomatous habit and rugose, widely ovate laminae, but it is different in having elongated (vs. congested) rhizomes, zygomorphic androecium (vs. actinomorphic or subactinomorphic), stamens 38−50 (vs. 65−100) and sparsely red hirsute ovary (vs. glabrous).
Etymology: The species is named in honor of Nguyen
Thanh Tu, who has made an outstanding contribution to
the conservation of the Ha Tinh langur (Trachypithecus
hatinhensis) population in Tuyen Hoa district, Quang
Binh province.
Trinh Ngoc Bon, Joachim Gratzfeld, Truong Thi Anh Tuyet and Che-Wei Lin. 2023. Begonia tui, A New Species of Begonia sect. Coelocentrum from Quang Binh Province, Central Vietnam. Taiwania. 68(4); 412-416. DOI: 10.6165/tai.2023.68.412 taiwania.NTU.edu.tw/abstract/1957
